Sleeved projectiles

ABSTRACT

Projectile ( 10 ) is for use with barrel assemblies of the type having a plurality of axially disposed projectiles within a bore and wherein discrete propellant charges are provided for propelling respective projectiles sequentially from the bore. Projectile ( 10 ) comprises expandable sleeve ( 11 ) encircling at least part of core ( 12 ). Sleeve ( 11 ) and core ( 12 ) have wedging surfaces ( 14 ) operable to deform trailing part ( 21 ) of sleeve ( 11 ) into sealing engagement with the bore in response to pressures exerted on projectile ( 10 ). When projectiles ( 10 ) are axially disposed in the bore, rear face ( 24 ) of the leading projectile cooperates with leading face ( 20 ) of the trailing projectile to define a discrete space about spine ( 23 ) for receipt of the propellant charge. Sleeve ( 11 ) is retained about core ( 12 ) during travel to the target.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to projectiles for use with barrelassemblies having a plurality of projectiles axially disposed within thebarrel and which projectiles are associated with discrete propellantcharges for propelling the projectiles sequentially through the muzzleof the barrel.

[0003] 2. Discussion of the Background Art

[0004] Our earlier patent applications relate to small arms, mortars andlarge bore rounds and the like and this invention relates to rounds forsuch weapons.

[0005] Trials of a handgun according to aspects of our earlier patentapplications have indicated that the two-part small calibre projectileshave a tendency to separate in flight especially when they tumble. Inone aspect this invention aims to provide a suitable projectile assemblyin which the parts remain intact as a streamlined projectile duringpassage to a target.

SUMMARY OF THE INVENTION

[0006] We have now found a projectile for use with barrel assemblies ofthe type having a plurality of projectiles axially disposed within abarrel having a bore and a muzzle and which projectiles are associatedwith discrete propellant charges for propelling said projectilessequentially through the muzzle of the barrel, said projectilescomprising an expandable sleeve for engagement with the bore of thebarrel and a projectile core about which said sleeve is disposed,wherein said expandable sleeve and said projectile core have cooperatingsurfaces operable to deform said expandable sleeve into sealingengagement with the bore of the barrel in response to pressure exertedupon a leading face of the projectile, and wherein a rear workingsurface of a leading projectile and said leading face of a trailingprojectile are associated with a spacer permitting projectiles to beaxially disposed within said barrel to define a propellant space betweensaid leading projectile and said trailing projectile and wherein saidsleeve is retained about said projectile core during travel to thetarget.

[0007] In a first preferred embodiment of the present invention thespacer may be integrally formed with the projectile core. In thisembodiment the projectile core may take the form of a spine that extendsaxially through the barrel in abutment for maintaining said propellantspace. In this first embodiment the present invention provides aprojectile for use with barrel assemblies of the type having a pluralityof projectiles axially disposed within a barrel having a bore and amuzzle and which projectiles are associated with discrete propellantcharges for propelling said projectiles sequentially through the muzzleof the barrel, said projectiles comprising an expandable sleeve forengagement with the bore of the barrel and a projectile core about whichsaid sleeve is disposed, wherein said expandable sleeve and saidprojectile core have cooperating surfaces operable to deform saidexpandable sleeve into sealing engagement with the bore of the barrel inresponse to pressure exerted upon a leading face of the projectilewherein said projectile core comprises a sub-calibre spacer extendingrearward from the body part to abut the leading face of a trailingprojectile permitting projectiles to be axially disposed within saidbarrel to define a propellant space between said leading projectile andsaid trailing projectile and wherein said sleeve is retained about saidprojectile core during travel to the target.

[0008] In a second preferred embodiment of the present invention thespacer may be separate from the projectile. In this embodiment thespacer may take the form of a propellant tube that extends axiallythrough the barrel in abutment with adjacent projectiles and which tubemaintains said propellant space within the walls of the tube. In thissecond embodiment the present invention provides a projectile for usewith barrel assemblies of the type having a plurality of projectilesaxially disposed within a barrel having a bore and a muzzle and whichprojectiles are associated with discrete propellant charges forpropelling said projectiles sequentially through the muzzle of thebarrel, said projectiles comprising an expandable sleeve for engagementwith the bore of the barrel and a projectile core about which saidsleeve is disposed, wherein said expandable sleeve and said projectilecore have cooperating surfaces operable to deform said expandable sleeveinto sealing engagement with the bore of the barrel in response topressure exerted upon a leading face of the projectile, and wherein arear working surface of a leading projectile and said leading face of atrailing projectile are in abutment with a combustible spacer tubepermitting projectiles to be axially disposed within said barrel todefine a propellant space between said leading projectile and saidtrailing projectile and wherein said sleeve is retained about saidprojectile core during travel to the target.

[0009] The present invention has particular application to barrelassemblies of the type described in International Patent ApplicationNos. PCT/AU94/00124 and PCT/AU96/00459. Such barrel assemblies include abarrel; a plurality of projectiles axially disposed within the barrelfor operative sealing engagement with the bore of the barrel, anddiscrete propellant charges for propelling respective projectilessequentially through the muzzle of the barrel.

[0010] The overall shape of the projectile, including the projectilecore and the expandable sleeve may be conventionally shaped dart-like,generally spherical or any other convenient shape. The projectile mayalso include fins that may advantageously be offset to generate astabilising spin as the dart is propelled from a barrel that may be asmooth-bored barrel.

[0011] The projectile charge is located in the propellant space and maybe formed as a solid block to assist in loading the barrel assemblies.Alternatively the propellant charge may be encased and may include anembedded primer having external contact means adapted for contacting apre-positioned electrical contact associated with the barrel. Forexample the primer could be provided with a sprung contact which may beretracted to enable insertion of the cased charge into the barrel and tospring out into a barrel aperture upon alignment with that aperture foroperative contact with its mating barrel contact. If desired the outercase may be consumable or may chemically assist the propellant burn.Furthermore an assembly of stacked and bonded or separate cased chargesand projectiles may be provided to facilitate the reloading of a barrel.

[0012] The barrel may be non-metallic and the bore of the barrel mayinclude recesses that may fully or partly accommodate the ignitionmeans. In this configuration the barrel may house electrical conductorswhich facilitate electrical communication between the control means andignition means. This configuration may be utilised for disposable barrelassemblies that have a limited firing life and the ignition means andcontrol wire or wires therefor can be integrally manufactured with thebarrel.

[0013] A barrel assembly may alternatively include ignition apertures inthe barrel and the ignition means are disposed outside the barrel andadjacent the apertures. The barrel may be surrounded by a non-metallicouter barrel which may include recesses adapted to accommodate theignition means. The outer barrel may also house electrical conductorswhich facilitate electrical communication between the control means andignition means. The outer barrel may be formed as a laminated plasticsbarrel which may include a printed circuit laminate for the ignitionmeans.

[0014] The electrical ignition for sequentially igniting the propellantcharges of a barrel assembly may preferably include the steps ofigniting the leading propellant charge by sending an ignition signalthrough the stacked projectiles, and causing ignition of the leadingpropellant charge to arm the next propellant charge for actuation by thenext ignition signal. Suitably all propellant charges inwardly from theend of a loaded barrel are disarmed by the insertion of respectiveinsulating fuses disposed between normally closed electrical contacts.

[0015] Ignition of the propellant may be achieved electrically orignition may utilise conventional firing pin type methods such as byusing a centre-fire primer igniting the outermost projectile andcontrolled consequent ignition causing sequential ignition of thepropellant charge of subsequent rounds. This may be achieved bycontrolled rearward leakage of combustion gases or controlled burning offuse columns extending through the projectiles or the barrel.

[0016] In another form the ignition is electronically controlled withrespective propellant charges being associated with primers which aretriggered by distinctive ignition signals. For example the primers inthe stacked propellant charges may be sequenced for increasing pulsewidth ignition requirements whereby electronic controls may selectivelysend ignition pulses of increasing pulse widths to ignite the propellantcharges sequentially in a selected time order. Preferably however thepropellant charges are ignited by a set pulse width signal and burningof the leading propellant charge arms the next propellant charge foractuation by the next emitted pulse.

[0017] Suitably in such embodiments all propellant charges inwardly fromthe end of a loaded barrel are disarmed by the insertion of respectiveinsulating fuses disposed between insertion of respective insulatingfuses disposed between normally closed electrical contacts, the fusesbeing set to burn to enable the contacts to close upon transmission of asuitable triggering signal and each insulating fuse being open to arespective leading propellant charge for ignition thereby.

[0018] A number of projectiles can be fired simultaneously, or in quicksuccession, or in response to repetitive manual actuation of a trigger,for example. In such arrangements the electrical signal may be carriedexternally of the barrel or it may be carried through the superimposedprojectiles which may clip on to one another to continue the electricalcircuit through the barrel, or abut in electrical contact with oneanother. the projectiles may carry the control circuit or they may forma circuit with the barrel.

[0019] The projectile of the present invention comprises an expandablesleeve for engagement with the bore of the barrel and a projectile coreabout which said sleeve is disposed. The expandable sleeve andprojectile core have cooperating surfaces operable to deform saidexpandable sleeve into sealing engagement with the bore of the barrel inresponse to pressure exerted upon a leading face of the projectile. Inone preferred form the cooperating surfaces may be complementary wedgingsurfaces. Where pressure, such as during loading or tamping of theprojectiles into the barrel assembly or when a propellant charge isdetonated in advance of the projectile, is exerted on the leading faceof the projectile the cooperating surfaces deform the expandable sleeveinto sealing engagement with the bore of the barrel.

[0020] The projectile core may comprise a relatively hard mandrelportion which cooperates with a deformable annular sleeve that may bemoulded about the mandrel to form a unitary projectile which relies onmaterial deformation of the sleeve for outward expansion about themandrel portion into sealing engagement with the bore of the barrel.

[0021] In one form the projectile core may include a forwardly taperingwedging surface and the expandable sleeve includes a complimentarysurface that causes the sleeve to expand as the sleeve moves rearwardrelative to the core. The sleeve suitably includes a skirt portion thatexpands outwardly when subject to an in-barrel load. The sealing may beeffected by inserting the projectiles into a heated barrel that shrinksonto respective sealing portions of the projectiles.

[0022] Alternatively the projectile core may include a rearwardlytapering wedging surface and the expandable sleeve includes acomplimentary surface that causes the sleeve to expand as the core movesrearward relative to the sleeve.

[0023] Preferably the sleeve engages with a leading or trailing portionof the core to deform into operative sealing engagement with said bore.However sleeve could expand about an intermediate portion of the bodyinto operative sealing engagement with said bore if desired.

[0024] The sleeve is retained about said projectile core during travelto the target. The sleeve may be retained about the core by at least oneshoulder located on either or both of the sleeve and core. In one formthe shoulder may be engaged with a recess on the other component.Alternatively the at least one shoulder may engage at least one end ofthe other component. The shoulder engages the other component in amanner that permits limited relative movement such that the sleeve cansealably and releasably engage the bore. In one form the sleeve mayinclude an inwardly disposed shoulder for engagement with a recess inthe core. Alternatively the core may include an outwardly disposedshoulder for engagement with a corresponding recess in the sleeve.

[0025] In another form the sleeve may include a shoulder for engagementwith the end of the core having the maximum diameter and wherein thecore is tapered and sleeve has a correspondingly tapered surface.

[0026] In the first preferred embodiment of the present invention theprojectile core incorporates the spacer integrally formed therewith.Suitably the projectile core may be in the form of a spine incorporatinga sub-calibre spacer that extends rearwardly from the projectile core.It will be understood that by the term sub-calibre it is meant having adiameter substantially less than that of the bore of the barrel. Thepropellant space is provided about the spacer.

[0027] In one form the projectile cores may be in end-to-end abutmentwith the rearwardly extending spacer engaging the leading face of thetrailing projectile. In this configuration the sleeve may be retained onthe core during flight by at least one shoulder on the sleeve and/or thecore, which shoulder engages with a complimentary recess in the othercomponent.

[0028] The spine may extend into a passage formed through the sleeve andthe sleeve may be retained on the spine by means of a cap engageablewith the inserted end of the spine so as to prevent withdrawal of thespine part from the sleeve but permitting limited axial movementtherebetween for effecting an operative seal between the sleeve and thebore of the barrel. Alternatively the spine may extend into a blindpassage formed in the rear end of the sleeve and be retained by means ofa collar about the spine and engageable with said rear end so as toprevent withdrawal of the spine from the sleeve but permitting limitedaxial movement therebetween for effecting an operative seal between thesleeve and the bore of the barrel.

[0029] If desired the spine may extend through a passage formed throughthe sleeve with its leading part splaying or being formed, such as byfolding, swaging or peening, so as to extend outwardly beyond thethrough passage so as to prevent withdrawal of the spine from the sleevebut permitting limited axial movement therebetween for effecting anoperative seal between the sleeve and the bore of the barrel.

[0030] Similarly the trailing portion of a sleeve formed with a blindpassage may incorporate a shoulder or otherwise contract behind or beformed, such as by folding, swaging or peening, so as to extend behindthe spine so as to prevent withdrawal of the spine from the sleeve butpermitting limited axial movement therebetween for effecting anoperative seal between the sleeve and the bore of the barrel.

[0031] Suitably a leading part of the core is a frusto-conical portionhaving a cone angle in the range of 5° to 15° and suitably the trailingend of the frusto-conical head portion terminates in close proximitywith the bore so as to expand only a relatively thin trailing portion ofthe sleeve into operative sealing engagement with the bore.

[0032] In the second embodiment of the present invention the spacer isin the form of a spacer tube and may house the propellant charge.

[0033] In one form the projectiles are maintained in spaced apartrelationship in the barrel by a spacer tube which contains thepropellant. The spacer tube is suitably formed as a rigid combustibletube which will combust with the propellant. Alternatively the spacertube may be formed of non combustible material and be discharged withthe projectile and discarded in flight, carried with the projectile orpushed out by a following round.

[0034] The spacer may extend through the propellant space and theprojectile head whereby compressive loads are transmitted directlythrough abutting adjacent spacer assemblies. In such configurations, thespacer assembly may add support to the extension means that may be athin cylindrical rear portion of the projectile head. Furthermore theextension means may form an operative sealing contact with the bore ofthe barrel to prevent burn leakage past the projectile head.

[0035] Complimentary surfaces may also be disposed on the spacer tubeand leading face of the projectile respectively whereby the spacer tubeis urged into engagement with the bore of the barrel in response torelative axial compression between the spacer tube and the leading faceof the projectile. In such arrangement the projectile and spacer tubemay be loaded into the barrel and thereafter an axial displacement iscaused to ensure good sealing between the spacer tube and barrel.

[0036] The spacer assembly may include a rigid collar which extendsoutwardly to engage a thin cylindrical rear portion of the malleableprojectile head inoperative sealing contact with the bore of the barrelsuch that axially compressive loads are transmitted directly betweenspacer assemblies thereby avoiding deformation of the malleableprojectile head.

[0037] In another form of the invention, the projectiles may be adaptedfor seating and/or location within circumferential grooves or by annularribs in the bore or in rifling grooves in the bore and may include ametal jacket encasing at least the outer end portion of the projectile.The projectile may be provided with contractible peripheral locatingrings which extend outwardly into annular grooves in the barrel andwhich retract into the projectile upon firing to permit its free passagethrough the barrel.

[0038] The projectile itself may contain a guidance system anddeployable flight means enabling it to be remotely guided to a target.

[0039] In a one aspect, this invention generally provides a specialpurpose round including a sleeve that engages with the bore of thebarrel and a projectile core extending centrally through the sleevewherein the sleeve has a leading end portion forming an annular recessabout the leading portion of the core.

[0040] The sleeve may be formed as a discarding sabot that can beconfigured to discard upon impact with a target. In certain applicationsthe sleeve would suitably be formed as a low mass part of a lightweightmaterial such as aluminium, magnesium, manganese or similar metal or ofa suitable plastics material, and the core would be formed of a highmass dense material such as lead or a composite of lead. The core may beprovided with reinforcing such as steel strakes to provide an effectiveanvil for expanding the sleeve. Such applications may includearmour-piercing applications.

[0041] Suitably in such a round the core is in the form of an elongatestreamlined body with much of the rearwardly expanding nose portionproud of the surrounding sabotted sleeve so as to facilitate rearwarddiscarding of the sabotted sleeve from the core while preventing forwarddislodgment during flight so as to enable the energy imparted to thesabotted sleeve by the propellant to be imparted to the core.

[0042] Alternatively the sleeve may be formed so as to have maximumterminal effect upon impact with a target. In such applications thesleeve would suitably be formed as a high mass part of a dense materialsuch lead or a composite or alloy of lead and other material. The corewould suitably be formed as a low mass part of a lightweight materialsuch as aluminium, magnesium, manganese or similar metal or of asuitable plastics material. Such rounds are useful in police work, forexample, where a suspect may be fired upon in a building occupied byother people. In such circumstances it is desirably that stray shotsshould not penetrate walls and the like and pose a danger to people inadjacent rooms.

[0043] Suitably a majority of the trailing face of the outer part isexposed to the propellant gases.

BRIEF DETAILS OF THE DRAWINGS

[0044] In order that this invention may be more readily understood andput into practical effect reference will now be made to the accompanyingdrawings which illustrate a preferred embodiment of the inventionwherein:

[0045] FIGS. 1 to 3 each illustrates a 9 mm projectile assembly suitablefor use with a hand gun;

[0046]FIG. 4 illustrates a special purpose projectile assembly adaptedfor target retention;

[0047]FIG. 5 illustrates yet another special purpose projectile assemblyadapted for penetrating a target;

[0048] FIGS. 6 to 9 illustrate large bore rounds, suitably for barrelsin the 100 to 200 mm calibre range, and

[0049]FIG. 10 illustrates a multi-barrel weapon for the projectilesillustrated in FIGS. 6 to 8.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0050] The projectile assembly 10 illustrated in FIG. 1 has an outerbody part 11 formed of lead which engages the bore of the barrel inwhich it is housed and a steel spine part 12 formed with a mediallydisposed forwardly reducing anvil portion 13 which extends into acomplementary passage 14 formed in the body part 11.

[0051] The spine part 12 has cylindrical lands 15 and 16 at its leadingend. The land 15 engages slidably with a leading cylindrical passage 17of the outer body part 11 and the land 16 engages captively with acollar 18 of a retaining cap 19, such as by being an interference fittherewith. The cap 19 has a leading end wall 20 which extends outwardlybeyond the passage 17 and which is spaced longitudinally from the bodypart 11 so as to retain the outer body part 11 for limited longitudinalmovement along the spine part 12.

[0052] As illustrated the taper of the anvil portion 13 is greater thanthe corresponding taper of the complementary passage 14 so that thetrailing end 21 thereof is the first portion to be engaged by the anvilportion 13 whereby in use, rearward movement of the body part 11 alongthe spine part 12 results in an outward splaying of the trailing part 21into operative sealing engagement with the bore of the barrel in whichit is housed.

[0053] Further rearward movement, will cause engagement of the anvilportion with the full surface of the passage 14 providing a progressiveincrease in resistance to rearward movement of the body part 11 due to acorresponding increase in resistance to radial expansion provided by thebody part 11.

[0054] In this embodiment the nose cap 19 is acted upon by pressure frompropellant gases from the leading round and thus some of resultantrearward force therefrom is resisted directly by the spine part 12. As aconsequence the volume of propellant which may be stored about the rearspine part 23 is less than could be accommodated in a projectileassembly 25 as illustrated in FIG. 2 which has the full front face ofthe outer part 26 exposed to pressure from propellant gases and beingresisted to a large extent by being wedged into sealing engagement withthe bore of a barrel in which it is housed. The trailing face 24 of thespine accommodates the cap 19.

[0055] The projectile assembly 10 is suited for a revolver or othershort range weapon whereas the projectile assembly 25 which may have areduced diameter or more elongated rear spine part 27 as it copes withless of the reaction force, can be utilised in a longer range weapon.

[0056] The projectile assembly 30 illustrated in FIG. 3 is similar tothe FIG. 2 embodiment. However this projectile assembly 30 has aretaining plate 31 clipped to or retained on the rear end part 32 of thebody part 33 so as to prevent in-flight separation of the spine part 34from the body part 33.

[0057] The projectile assembly 40 illustrated in FIG. 4 is a specialpurpose round having an body part 41 formed so as to have maximumterminal effect upon impact with a target. The body part 41 engages withthe bore of the barrel in which it is supported and its positioningtherein is effected by the spine part 42, which as in the embodiments ofFIGS. 1 and 5, stacks with complementary spine parts to form acontinuous column extending centrally through the barrel with the bodyparts 41 evenly spaced therealong.

[0058] In the illustrated embodiment the body part 41 is formed fromlead and the spine part is formed from aluminium.

[0059] In use, if such a round is fired from a revolver hits a wall in adwelling, for example, it will not penetrate the wall. Thus it can beused by police in close quarters without fear of injuring someone out ofthe user's sight.

[0060] The projectile assembly 50 illustrated in FIG. 5 has a spine part51 in the form of an elongate streamlined penetrating body formed oflead which is assisted by a lightweight body part 52 forming a sabotwhich discards in flight. For this purpose the front end of the bodypart is cupped to provide resistance to high speed flight and its innerportion 53 extends only slightly forward of the major diameter of thespine part 51 so that it can readily slide backwards away from the spinepart 51 and discard.

[0061] In this arrangement most of the propellant gases act upon therear face of the sabot 52 and impart more energy to the spine part thancould otherwise be imparted thereto. Thus the projectile 50 will exitthe muzzle of its supporting barrel at high speed whereupon the sabotwill discard leaving the heavy energy boosted spine part travelling to atarget.

[0062] The large bore rounds 60, 70 illustrated in FIGS. 6 and 7 eachhave a large heavy projectile 61, 71 such as 155 mm diameter projectileswhich may include high explosives provided with an outer sealing part62, 72 engaged in a barrel 63, 73 and surrounding a trailing portion ofthe projectile and engaged therewith in a wedging manner wherebyrearward of the projectile relative to the sealing part will expandedthe sealing part into sealing engagement with the bore of the barrel inwhich they are seated, such as the barrels 100 illustrated in FIG. 10.

[0063] For this purpose each sealing part is supported fixedly in itsbarrel 63, 73 as part of a rigid column composed of stacked sealingparts 62,72 and alternate combustible structural tubes 64, 74 containingthe propellant 69, 79.

[0064] The sealing parts 62, 72 have inner frusto-conical surfaces 65,75 interrupted by an annular recess 66, 76 which fits loosely over anoutwardly extending band 67,77 encircling the complementary outerfrusto-conical surface 68, 78 of the projectile 61. This band 67, 77maintains engagement of the sealing part 62, 72 on the projectile duringflight and handling.

[0065]FIG. 8 illustrates a further projectile 80 similar to theembodiment of FIG. 7 but wherein the spacer tubes 81 have enlarged endportions 82, 83 to provide larger mating load transfer faces 84, 85.

[0066] The projectile assembly 90 illustrated in FIG. 9 utilises aseries of circumferentially extending ripples 91 formed on the sealingmeans 92 which mate with complementary grooves 93 in the barrel tomaintain the projectile 94 in spaced apart relationship in the barreland to hold the sealing means 92 against rearward movement in lieu ofthe combustible structural tubes such that the sealing means 92 may beexpanded outwardly by rearward movement of the projectile 94 to sealagainst propellant gases from a leading round travelling rearward to thefollowing propellant charge. If desired, the ripples may be formed as aspiral thread so as to assist in sealing engagement with and location ina barrel.

[0067] As illustrated in FIG. 10 the projectile assemblies 60, 70, 80and 90 may be accommodated in replaceable barrels 90 supportedvertically in a pod 91. The barrels may be cushioned by recoil controlmeans 92 and they may be adapted to be extended slightly from the podprior to firing.

[0068] It will of course be realised that the above has been given onlyby way of illustrative example of the invention and that all suchmodifications and variations thereto as would be apparent to personsskilled in the art are deemed to fall within the broad scope and ambitof the invention as is herein set forth in the following claims.

1. A projectile for use with barrel assemblies of the type having aplurality of projectiles axially disposed within a barrel having a boreand a muzzle and which projectiles are associated with discretepropellant charges for propelling said projectiles sequentially throughthe muzzle of the barrel, said projectiles comprising an expandablesleeve for engagement with the bore of the barrel and a projectile coreabout which said sleeve is disposed, wherein said expandable sleeve andsaid projectile core have cooperating surfaces operable to deform saidexpandable sleeve into sealing engagement with the bore of the barrel inresponse to pressure exerted upon a leading face of the projectilewherein said projectile core comprises a sub-calibre spacer extendingrearward from the body part to abut the leading face of a trailingprojectile permitting projectiles to be axially disposed within saidbarrel to define a propellant space between said leading projectile andsaid trailing projectile and wherein said sleeve is retained about saidprojectile core during travel to the target.
 2. A projectile accordingto claim 1 wherein the cooperating surfaces are in the form ofcomplementary wedging surfaces.
 3. A projectile according to eitherclaim 1 or claim 2 wherein the projectile core comprises a relativelyhard mandrel portion which cooperates with a deformable annular sleeve.4. A projectile according to any one of claims 1 to 3 wherein theprojectile core includes a forwardly tapering wedging surface and theexpandable sleeve includes a complimentary surface that causes thesleeve to expand as the sleeve moves rearward relative to the core.
 5. Aprojectile according to any one of claim 1 to 4 wherein the projectilecore may include a rearwardly tapering wedging surface and theexpandable sleeve includes a complimentary surface that causes thesleeve to expand as the core moves rearward relative to the sleeve.
 6. Aprojectile according to any one of claims 1 to 5 wherein the sleeve isretained about the core by at least one shoulder located on either oneor both of the sleeve and the core.
 7. A projectile according to claim 6wherein the shoulder is engaged with a corresponding recess on the othercomponent.
 8. A projectile according to any one of claims 1 to 7 whereinthe projectile core is in the form of a spine incorporating asub-calibre spacer that extends rearwardly from the projectile core. 9.A projectile according to any one of claims 1 to 7 wherein core extendsinto a passage formed through the sleeve and the sleeve is retained onthe core by means of a cap engageable with the inserted end of the coreso as to prevent withdrawal of the core from the sleeve but permittinglimited axial movement therebetween for effecting an operative sealbetween the sleeve and the bore of the barrel.
 10. A projectileaccording to any one of claims 1 to 7 wherein the core extends into ablind passage formed in the rear end of the sleeve and be retained bymeans of a collar about the core and engageable with said rear end so asto prevent withdrawal of the core from the sleeve but permitting limitedaxial movement therebetween for effecting an operative seal between thesleeve and the bore of the barrel.
 11. A projectile according to claim10 wherein the trailing portion of a sleeve formed with a blind passageincorporates a shoulder so as to extend behind the core so as to preventwithdrawal of the core from the sleeve but permitting limited axialmovement therebetween for effecting an operative seal between the sleeveand the bore of the barrel.
 12. A projectile according to claim 11wherein the shoulder is engaged with a corresponding recess on the othercomponent.
 13. A projectile according to any one of claims 1 to 12wherein the sleeve is formed as a discarding sabot configured to discardupon impact with a target.
 14. A projectile according to claim 13wherein the sleeve is formed as a low mass part of a lightweightmaterial selected from the group consisting of aluminium, magnesium,manganese or of a suitable plastics material.
 15. A projectile accordingto either claim 13 or claim 14 wherein the core is formed of a high massdense material selected from the group consisting of lead or a compositeof lead.
 16. A projectile according to claim 12 wherein the sleeveformed as a high mass part of a dense material selected from the groupconsisting of lead or a composite or alloy of lead.
 17. A projectileaccording to either claim 12 or claim 16 wherein the core formed as alow mass part of a lightweight material selected from the groupconsisting of aluminium, magnesium, manganese or of a suitable plasticsmaterial.
 18. A projectile for use with barrel assemblies of the typehaving a plurality of projectiles axially disposed within a barrelhaving a bore and a muzzle and which projectiles are associated withdiscrete propellant charges for propelling said projectiles sequentiallythrough the muzzle of the barrel, said projectiles comprising anexpandable sleeve for engagement with the bore of the barrel and aprojectile core about which said sleeve is disposed, wherein saidexpandable sleeve and said projectile core have cooperating surfacesoperable to deform said expandable sleeve into sealing engagement withthe bore of the barrel in response to pressure exerted upon a leadingface of the projectile, and wherein a rear working surface of a leadingprojectile and said leading face of a trailing projectile are inabutment with a combustible spacer tube permitting projectiles to beaxially disposed within said barrel to define a propellant space betweensaid leading projectile and said trailing projectile and wherein saidsleeve is retained about said projectile core during travel to thetarget.
 19. A projectile according to claim 18 wherein the cooperatingsurfaces are in the form of complementary wedging surfaces.
 20. Aprojectile according to either claim 18 or claim 19 wherein theprojectile core comprises a relatively hard mandrel portion whichcooperates with a deformable annular sleeve.
 21. A projectile accordingto claim 20 wherein the annular sleeve that is moulded about the mandrelto form a unitary projectile which relies on material deformation of thesleeve for outward expansion about the mandrel portion into sealingengagement with the bore of the barrel
 22. A projectile according to anyone of claims 18 to 21 wherein the projectile core includes a forwardlytapering wedging surface and the expandable sleeve includes acomplimentary surface that causes the sleeve to expand as the sleevemoves rearward relative to the core.
 23. A projectile according to anyone of claims 18 to 21 wherein the projectile core may include arearwardly tapering wedging surface and the expandable sleeve includes acomplimentary surface that causes the sleeve to expand as the core movesrearward relative to the sleeve.
 24. A projectile according to any oneof claims 18 to 23 wherein the sleeve is retained about the core by atleast one shoulder located on either one or both of the sleeve and thecore
 25. A projectile according to claim 24 wherein the shoulder isengaged with a corresponding recess on the other component
 26. Aprojectile according to any one of claims 18 to 25 wherein theprojectiles are maintained in spaced apart relationship in the barrel bya spacer tube which contains the propellant.
 27. A projectile accordingto claims 18 to 26 wherein the combustible spacer tube is a rigid tubewhich will combust with the propellant.
 28. A projectile according toclaims 18 to 27 wherein complimentary surfaces are disposed on thespacer tube and leading face of the projectile respectively whereby thespacer tube is urged into engagement with the bore of the barrel inresponse to relative axial compression between the spacer tube and theleading face of the projectile.
 29. A projectile according to any one ofclaims 1 to 28 wherein the sleeve engages with the bore of the barreland a projectile core extending centrally through the sleeve wherein thesleeve has a leading end portion forming an annular recess about theleading portion of the core.
 30. A projectile according to claim 29wherein the sleeve is formed as a discarding sabot configured to discardupon impact with a target.
 31. A projectile according to claim 30wherein the sleeve is formed as a low mass part of a lightweightmaterial selected from the group consisting of aluminium, magnesium,manganese or of a suitable plastics material.
 32. A projectile accordingto either claim 30 or 31 wherein the core is formed of a high mass densematerial selected from the group consisting of lead or a composite oflead.
 33. A projectile according to claim 29 wherein the sleeve formedas a high mass part of a dense material selected from the groupconsisting of lead or a composite or alloy of lead.
 34. A projectileaccording to either claim 29 or 33 wherein the core formed as a low masspart of a lightweight material selected from the group consisting ofaluminium, magnesium, manganese or of a suitable plastics material.